Paved structures (e.g., asphalt and concrete) that vehicles travel over, such as bridge decks, roadways, parking structures, runways, taxiways, and so on, deteriorate over time. The deterioration of these paved structures may be caused by usage, environmental, and aging factors, resulting in damage to the surface of the road, to rebar within pavement, to pilings supporting the road, and so on. One usage factor is vehicle weight. As the weight of a vehicle increases, the road damage (e.g., buckling and cracking) increases due to the increased stress on the road. Other usage factors include use of chains or studded tires. One environmental factor is temperature. During winter, water that seeps under a road may freeze and expand, causing road damage (e.g., potholes). Other environmental factors include earthquakes, snow, rain, and so on.
Regardless of how a paved structure is damaged, a damaged paved structure may present a danger to vehicles and their passengers that travel over the damaged portions of the paved structure. In addition, the damage may also present a danger to pedestrians, other vehicles, houses, and so on that happen to be nearby when a vehicle travels over a damaged portion. To minimize this danger, the paved structures may be periodically inspected. For example, a civil engineering firm may check paved structures on a regular basis (e.g., yearly) for the presence of new damage (e.g., cracks). Current inspection techniques include visual inspection augmented by chain dragging or hammering to detect changes in sound reverberations. These inspection techniques result in subjective, highly variable, and highly unreliable assessments, while also requiring that traffic be rerouted during the evaluation process.
It has been suggested that damage to paved structures be detected using ground-penetrating radar (“GPR”). However, each time the paved structure, roadway, or area is scanned, large amounts of data may be collected and processed. For example, the scan of a road may collect GPR return signals every few centimeters. A GPR system may generate image frames from the return signals and attempt to detect surface and subsurface damage from those image frames. Because GPR systems and their analysis techniques are typically expensive and computationally intensive, any possible road damage assessment by such techniques would likely be limited to only certain roads (e.g., bridge decks) and/or performed only on an infrequent basis. Such limited and infrequent road damage assessment fails to detect many types of road damage that may cause a serious safety hazard.